A wide variety of liquid handling apparatuses and pipettors are available and are capable of a wide variety of liquid handling functions, as appreciated by persons skilled in the art. Generally, a pipettor is utilized for aspirating and dispensing precise volumes of liquid, typically by air displacement. The pipettor includes a syringe coupled with a pipette tip. The syringe includes a piston that moves through a barrel. The pipette tip is coupled to the syringe such that an air path is established between the barrel and the pipette tip. The piston is driven manually or by a motor to alternately execute a forward stroke and backward stroke in the barrel. The forward stroke increases air pressure and thus can be utilized to dispense liquid from the pipette tip. The backward stroke creates suction and thus can be utilized to aspirate liquid into the pipette tip. One or more pipettors may be included in an automated pipetting device, which may be part of a liquid handling apparatus that utilizes liquid containers such as multi-well plates. The pipetting device may be movable to and from different multi-well plates located on a deck of the liquid handling apparatus. Thus, for instance, the pipettors may be operated to aspirate desired amounts of liquid from one multi-well plate into the pipette tips coupled to the pipettors, transport the liquid held in the pipette tips to another multi-well plate, and dispense the liquid from the pipette tips into desired wells of that other multi-well plate.
Pipette tips are available in many different sizes (e.g., 10 μL, 50 μL, 300 μL, 1 mL, 5 mL, etc.) and geometries, including both disposable and non-disposable types. Different procedures or protocols may require different pipette tips (in terms of size and/or type), and in some cases the same procedure or protocol may require the use of different pipette tips. Some existing pipetting devices have the ability to accommodate different styles of pipette tips, but require a user to manually change pipette tips between automated procedures or protocols. Some existing pipetting devices have the ability to automatically change disposable tips and non-disposable tips during a procedure or protocol, but require the ends of those tips (which are to be coupled to the syringes) to have the same interface geometry. To accommodate disposable tips sized to hold large volumes (e.g., 1000 μL), the interface geometry is designed around those large tips. Thus, smaller volume disposable tips (e.g., 10 μL) must use the same interface to the pipettor as is used by the much larger tips, resulting for instance in a smaller volume tip that is not optimally designed for its small volume and use or application. For example, the interface of the smaller volume tip is much larger than desired. Moreover, because the interface on the smaller volume tips is forced to be large (again, to be interchangeable with larger volume tips in conjunction with the same pipettor), the smaller volume tips cannot be placed in a grid next to each other at the relatively small spacing (e.g., 4.5 mm) required to access the adjacent wells of a multi-well (e.g., 384 well) plate of standard size. In addition, different procedures or protocols may require the use of multi-channel pipetting devices and/or single-channel pipetting devices. These two types of pipetting devices often have different interfaces, and thus the same size or type of pipette tip may not be usable on both a multi-channel pipetting devices and a single-channel pipetting devices.
Generally, there is an ongoing need for increasing the level of automation provided by liquid handling and pipetting instruments to increase throughput and the “walk away” time afforded to users of such instruments. In particular, there is a need for increasing the level of interchangeability among different types and sizes of pipette tips, and for automating the tasks of coupling pipette tips to syringes, decoupling pipette tips from syringes, and exchanging different pipette tips in an automated manner.